Modern vehicles commonly include a multitude of driver-assistance systems and expanded safety devices such as belt tighteners or airbags. To ensure proper functioning of these assistance or safety systems, precise knowledge of the current movement situation of the vehicle is required in most cases.
For example, acceleration sensors may detect the acceleration or deceleration of a vehicle in a certain direction, while rate-of-rotation sensors may detect twisting or a rotation of the vehicle about an axis.
Normally, a three-dimensional coordinate system X,Y,Z is used for this purpose, X denoting the longitudinal axis, Y the transverse axis, and Z the vertical axis of the vehicle. Roll-rate sensors, on the other hand, are able to detect a rotation of the vehicle about the X,Y,Z axes.
Conventional micromechanical combination modules may include a plurality of sensors, in particular three sensors, which have associated degrees of freedom, are frequently disposed. These may not necessarily be three acceleration sensors exclusively, or three roll-rate sensors or rotation sensors, but a combination of acceleration and rotation sensor is possible as well.
Different driver assistance system or safety systems may feature very individualized sensor combinations in this context.
For an ESP module, for example, a sensor having three degrees of freedom, i.e., generally a 3D sensor element, may be provided, which is able to detect an acceleration in the X and Y directions, as well as a rotation about the Z-axis. For a rollover sensor, on the other hand, a 3D sensor may measure an acceleration in the Y and Z-axes, and furthermore a rotation about the X-axis.
Such sensor modules, however, are mostly designed or optimized for a particular use. A simple exchange is therefore often impossible.